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Quasars serve as important cosmological probes and constructing accurate luminosity relations for them is essential for their use in cosmology. If the coefficients of quasar's luminosity relation vary with redshift, it could introduce biases into cosmological constraints derived from quasars. In this paper, we conduct a detailed analysis of the redshift variation in the X-ray luminosity and ultraviolet (UV) luminosity (\begin{document}$ L_\mathrm{X} $\end{document} ![]()
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-\begin{document}$ L_\mathrm{UV} $\end{document} ![]()
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) relations of quasars. For the standard \begin{document}$ L_\mathrm{X} $\end{document} ![]()
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-\begin{document}$ L_\mathrm{UV} $\end{document} ![]()
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relation, we find that the relation coefficients exhibit a strong and linear correlation with redshift, which is not attributable to the selection effect. Additionally, we examine two three-dimensional, redshift-evolving \begin{document}$ L_\mathrm{X} $\end{document} ![]()
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-\begin{document}$ L_\mathrm{UV} $\end{document} ![]()
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relations and find that the inclusion of a redshift-dependent term does not eliminate the impact of redshift evolution, as the relation coefficients continue to evolve with redshift. Finally, we construct a new \begin{document}$ L_\mathrm{X} $\end{document} ![]()
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-\begin{document}$ L_\mathrm{UV} $\end{document} ![]()
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relation in which the redshift evolution of the relation coefficients is nearly eliminated. Calibrating the luminosity relations using Hubble parameter measurements, we demonstrate that quasars utilizing our new relation yield effective constraints on cosmological parameters that are consistent with results from Planck CMB data, unlike constraints derived from the standard relation.
Quasars serve as important cosmological probes and constructing accurate luminosity relations for them is essential for their use in cosmology. If the coefficients of quasar's luminosity relation vary with redshift, it could introduce biases into cosmological constraints derived from quasars. In this paper, we conduct a detailed analysis of the redshift variation in the X-ray luminosity and ultraviolet (UV) luminosity (
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Since the quantum gravitational effects Barrow proposed that black hole horizon is "fractalized" into a sphereflake. Based on this issue, in this work we investigate the phase structure and stability of the Einstein-Power-Yang-Mills (EPYM) AdS black holes in the restricted phase space when the black hole event horizon is of the fractal structure. From the thermodynamical first law of the EPYM AdS black hole in the restricted phase space, we find that the mass parameter should be understood as the internal energy. And the Smarr relation of this system in the restricted phase space is not a homogeneous function due to the fractal structure, which is fully different from that of this system in the extended phase space. The corresponding fractal structure can be regarded as a phase transition probe. It is interesting that for the fixed central charge of the EPYM AdS black hole system with the fractal structure there also exists the supercritical phase transition as well as the standard EPYM AdS black hole system. Furthermore the effects of the fractal parameter ∆ and non-linear Yang-Mills parameter γ on the thermodynamical stability of this system are also investigated.
Since the quantum gravitational effects Barrow proposed that black hole horizon is "fractalized" into a sphereflake. Based on this issue, in this work we investigate the phase structure and stability of the Einstein-Power-Yang-Mills (EPYM) AdS black holes in the restricted phase space when the black hole event horizon is of the fractal structure. From the thermodynamical first law of the EPYM AdS black hole in the restricted phase space, we find that the mass parameter should be understood as the internal energy. And the Smarr relation of this system in the restricted phase space is not a homogeneous function due to the fractal structure, which is fully different from that of this system in the extended phase space. The corresponding fractal structure can be regarded as a phase transition probe. It is interesting that for the fixed central charge of the EPYM AdS black hole system with the fractal structure there also exists the supercritical phase transition as well as the standard EPYM AdS black hole system. Furthermore the effects of the fractal parameter ∆ and non-linear Yang-Mills parameter γ on the thermodynamical stability of this system are also investigated.
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The distribution of nuclei produced in the 40Ar + 232Th reaction has been studied at the gas-filled recoil separator (SHANS2) at the China Accelerator Facility for Superheavy Elements (CAFE2). The bombardment was carried out at a beam energy of 205 MeV and with the detection system installed at the focal plane. Forty-four isotopes heavier than 208Pb were observed. These isotopes were identified as the transfer reaction (or target-like) products, and their relative cross sections were extracted. Based on the mass distribution of these products, we exclude the possibility that they were produced by fusion-fission reactions, and thus may originate from quasi-fission of the 40Ar + 232Th reaction.
The distribution of nuclei produced in the 40Ar + 232Th reaction has been studied at the gas-filled recoil separator (SHANS2) at the China Accelerator Facility for Superheavy Elements (CAFE2). The bombardment was carried out at a beam energy of 205 MeV and with the detection system installed at the focal plane. Forty-four isotopes heavier than 208Pb were observed. These isotopes were identified as the transfer reaction (or target-like) products, and their relative cross sections were extracted. Based on the mass distribution of these products, we exclude the possibility that they were produced by fusion-fission reactions, and thus may originate from quasi-fission of the 40Ar + 232Th reaction.
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We analyze the recent data from the BESIII collaboration on the\begin{document}$ X(3872) $\end{document} ![]()
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state in the \begin{document}$ J/\psi\pi^+\pi^- $\end{document} ![]()
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and \begin{document}$ D^0\bar{D}^0\pi^0 $\end{document} ![]()
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decay channels. The quantum number and mass of the \begin{document}$ X(3872) $\end{document} ![]()
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state allow us to exploit the universal feature of the very near-threshold \begin{document}$ D\bar D^* $\end{document} ![]()
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scattering in the S wave. The analysis of \begin{document}$ J/\psi\pi^+\pi^- $\end{document} ![]()
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data and \begin{document}$ D^0\bar{D}^0\pi^0 $\end{document} ![]()
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data separately as well as the combined analysis of these data together, all support the conclusion that \begin{document}$ X(3872) $\end{document} ![]()
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is an extremely weakly bound charm meson molecule.
We analyze the recent data from the BESIII collaboration on the
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This paper investigates the neutrino transition magnetic moment in the\begin{document}$ U(1)_X $\end{document} ![]()
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SSM. \begin{document}$ U(1)_X $\end{document} ![]()
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SSM is the \begin{document}$ U(1) $\end{document} ![]()
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extension of Minimal Supersymmetric Standard Model (MSSM) and its local gauge group is extended to \begin{document}$ SU(3)_C\times SU(2)_L \times U(1)_Y\times U(1)_X $\end{document} ![]()
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. To obtain this model, three singlet new Higgs superfields and right-handed neutrinos are added to the MSSM, which can explain the results of neutrino oscillation experiments. The neutrino transition magnetic moment is induced by electroweak radiative corrections. By applying effective Lagrangian method and on-shell scheme, we study the associated Feynman diagrams and the transition magnetic moment of neutrinos in the model. We fit experimental data for neutrino mass variances and mixing angles. Based on the range of data selection, the influences of different sensitive parameters on the results are analysed. The numerical analysis shows that many parameters have an effect on the neutrino transition magnetic moment, such as \begin{document}$ g_X $\end{document} ![]()
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, \begin{document}$ M_2 $\end{document} ![]()
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, \begin{document}$ \mu $\end{document} ![]()
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, \begin{document}$ \lambda_H $\end{document} ![]()
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and \begin{document}$ g_{YX} $\end{document} ![]()
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. For our numerical results, the order of magnitude of \begin{document}$ \mu_{ij}^M/\mu_B $\end{document} ![]()
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is around \begin{document}$ 10^{-20} $\end{document} ![]()
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\begin{document}$ \sim $\end{document} ![]()
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\begin{document}$ 10^{-19} $\end{document} ![]()
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.
This paper investigates the neutrino transition magnetic moment in the
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Utilizing 4.5\begin{document}$ \text{fb}^{-1} $\end{document} ![]()
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of \begin{document}$ e^+e^- $\end{document} ![]()
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annihilation data collected at center-of-mass energies ranging from 4599.53 MeV to 4698.82 MeV by the BESIII detector at the BEPCII collider, we search for the singly Cabibbo-suppressed hadronic decays \begin{document}$ \Lambda_{c}^{+}\to\Sigma^{0} K^{+}\pi^{0} $\end{document} ![]()
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and \begin{document}$ \Lambda_{c}^{+}\to\Sigma^{0}K^{+} \pi^+ \pi^- $\end{document} ![]()
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with a single-tag method. No significant signals are observed for both decays. The upper limits on the branching fractions at the 90% confidence level are determined to be \begin{document}$ 5.0\times 10^{-4} $\end{document} ![]()
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for \begin{document}$ \Lambda_{c}^{+}\to\Sigma^{0} K^{+}\pi^{0} $\end{document} ![]()
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and \begin{document}$ 6.5\times 10^{-4} $\end{document} ![]()
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for \begin{document}$ \Lambda_c^{+}\to\Sigma^0K^{+}\pi^{+}\pi^{-} $\end{document} ![]()
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.
Utilizing 4.5
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This work presents an explanation of the nature of the island of inversion exhibited by the unstable nucleus 32Mg, through the applications of the axially deformed relativistic Hartree-Fock-Bogoliubov (D-RHFB) and the configuration-interaction relativistic Hartree-Fock (CI-RHF) models, which correspond to the Hartree-Fock-Bogoliubov level and beyond, respectively. Using the same Lagrangian PKA1, the D-RHFB and CI-RHF models demonstrate an excellent agreement with experimental data for the ground-state deformation and the low-lying excitation energies of 32Mg. Furthermore, a new insight into the nature of the island of inversion is implemented from the breaking of the pseudo-spin symmetry (PSS), in addition to the cross-shell excitation, both of which are essential to give rise to a stable deformation and a rotational collectivity for 32Mg. In particular, the exchange degrees of freedom, like the ρ-tensor coupling in PKA1, are illustrated to play a substantial role in determining the configuration interactions and the binding of the nucleus.
This work presents an explanation of the nature of the island of inversion exhibited by the unstable nucleus 32Mg, through the applications of the axially deformed relativistic Hartree-Fock-Bogoliubov (D-RHFB) and the configuration-interaction relativistic Hartree-Fock (CI-RHF) models, which correspond to the Hartree-Fock-Bogoliubov level and beyond, respectively. Using the same Lagrangian PKA1, the D-RHFB and CI-RHF models demonstrate an excellent agreement with experimental data for the ground-state deformation and the low-lying excitation energies of 32Mg. Furthermore, a new insight into the nature of the island of inversion is implemented from the breaking of the pseudo-spin symmetry (PSS), in addition to the cross-shell excitation, both of which are essential to give rise to a stable deformation and a rotational collectivity for 32Mg. In particular, the exchange degrees of freedom, like the ρ-tensor coupling in PKA1, are illustrated to play a substantial role in determining the configuration interactions and the binding of the nucleus.
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This study presents a comprehensive investigation of the true ternary fission for\begin{document}$ ^{248}\text{Cf} $\end{document} ![]()
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isotope. Using the Three-Cluster Model (\begin{document}$ \text{TCM} $\end{document} ![]()
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) based on the \begin{document}$ \text{WKB} $\end{document} ![]()
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approximation, detailed calculations were performed for all possible fragment configurations, considering the equatorial and the collinear geometries. The fragment charge numbers (Z) were systematically filtered within the range \begin{document}$ Z = 20 $\end{document} ![]()
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to \begin{document}$ Z = 52 $\end{document} ![]()
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, and all combinations were examined for three positional arrangements: the fragments \begin{document}$ A_{1} $\end{document} ![]()
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, \begin{document}$ A_{2} $\end{document} ![]()
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, and \begin{document}$ A_{3} $\end{document} ![]()
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occupying the middle position in the collinear geometry. For each combination, key quantities were calculated, including driving potential (\begin{document}$ \text{V - Q} $\end{document} ![]()
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), penetration probability (P), relative yield Y, decay constant (λ), and half-life (\begin{document}$ T_{\frac{1}{2}} $\end{document} ![]()
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). The selection of optimal fragment combinations was based on the higher penetration probability or the minimum driving potential, ensuring a systematic approach to identifying the most favorable fission configurations. Redundancy from permutations of \begin{document}$ Z_{1} $\end{document} ![]()
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, \begin{document}$ Z_{2} $\end{document} ![]()
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, and \begin{document}$ Z_{3} $\end{document} ![]()
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was eliminated by treating them equivalently. The results highlight the significant influence of fragment geometry and the nuclear structure, particularly shell effects, on the fission dynamics. This work provides new insights into the complex mechanisms of the true ternary fission, contributing to the broader understanding of nuclear stability and fragment distributions in such processes. Furthermore, the effects of fragments permutations, geometries and neutron emission through fission process are the novelty of this study relative to the similar researches.
This study presents a comprehensive investigation of the true ternary fission for
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The ground state properties of finite, bulk matter and neutron stars are investigated using the proposed effective interaction (HPU4) for the relativistic mean field model (RMF), that incorporates self and cross-couplings of σ, ω, and ρ mesons with nucleon. This interaction has been constructed by fitting data on finite nuclei's binding energies and charge radii, neutron skin (\begin{document}$ \Delta r_{\text{np}} $\end{document} ![]()
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) of \begin{document}$ ^{48} {\rm{Ca}}$\end{document} ![]()
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nucleus, and astrophysical observations of neutron stars' maximum masses. \begin{document}$ \Delta r_{\text{np}} $\end{document} ![]()
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(\begin{document}$ ^{48} {\rm{Ca}}$\end{document} ![]()
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) = 0.146±0.019 fm is achieved with soft symmetry energy (\begin{document}$ J_{0} $\end{document} ![]()
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= 27.91±1.31 MeV) and its corresponding slope (\begin{document}$ L_{0} $\end{document} ![]()
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= 42.85±14.26 MeV) at saturation density. An equation of state (EoS) having a composition of β- equilibrated nucleonic and leptonic matter is computed. The nuclear matter and neutron star properties are also analyzed for this interaction and agree well with the astrophysical observations, such as the NICER and GW170817 events. We also perform the statistical analysis to estimate the theoretical errors in coupling parameters, and neutron star observables, and to find the correlation coefficients. It is observed that neutron skin of \begin{document}$ ^{208} {\rm{Pb}}$\end{document} ![]()
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and \begin{document}$ ^{48} {\rm{Ca}}$\end{document} ![]()
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is strongly correlated and shows a strong dependence on \begin{document}$ J_{0} $\end{document} ![]()
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, \begin{document}$ L_{0} $\end{document} ![]()
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, and curvature of symmetry energy, \begin{document}$ K_{\text{sym}} $\end{document} ![]()
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as suggested from their correlations. A strong correlation of \begin{document}$ R_{1.4} $\end{document} ![]()
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with ρ-meson-nucleon coupling quantified by term \begin{document}$ g_{\rho N} $\end{document} ![]()
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, and mixed interaction terms, \begin{document}$ \sigma\rho_{\mu}\rho^{\mu} $\end{document} ![]()
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and \begin{document}$ \sigma^{2}\rho_{\mu}\rho^{\mu} $\end{document} ![]()
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is also observed.
The ground state properties of finite, bulk matter and neutron stars are investigated using the proposed effective interaction (HPU4) for the relativistic mean field model (RMF), that incorporates self and cross-couplings of σ, ω, and ρ mesons with nucleon. This interaction has been constructed by fitting data on finite nuclei's binding energies and charge radii, neutron skin (
Published:
, doi: 10.1088/1674-1137/adc4cb
Abstract:
A method for the treatment of the neutron-proton (np) isovector pairing correlations at finite temperature is developed within the path integral formalism. It generalizes the recently proposed model using a similar approach in the pairing between like-particles case. The pairing terms in the total Hamiltonian are written in a square form in order to facilitate the use of the Hubbard-Stratonovitch transformation. The expression for the partition function of the system is then established. The gap equations, as well as the expressions for the energy, the entropy and the heat capacity of the system are deduced. As a first step, the formalism is numerically applied to the schematic Richardson model. As a second step, the method is applied to nuclei such as\begin{document}$ N=Z $\end{document} ![]()
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using the single-particle energies of a deformed Woods-Saxon mean-field. The variations in the gap parameters, the excitation energy and the heat capacity are studied as functions of the temperature. It is shown that the overall behavior of these quantities is similar to their homologues in the standard FTBCS model. We note in particular the existence of critical temperatures beyond which the pairing vanish. Moreover, it appears that in the framework of the present approach, the pairing effects persist beyond the critical temperatures predicted by the FTBCS model in the pairing between like-particles case or its generalization in the np pairing case.
A method for the treatment of the neutron-proton (np) isovector pairing correlations at finite temperature is developed within the path integral formalism. It generalizes the recently proposed model using a similar approach in the pairing between like-particles case. The pairing terms in the total Hamiltonian are written in a square form in order to facilitate the use of the Hubbard-Stratonovitch transformation. The expression for the partition function of the system is then established. The gap equations, as well as the expressions for the energy, the entropy and the heat capacity of the system are deduced. As a first step, the formalism is numerically applied to the schematic Richardson model. As a second step, the method is applied to nuclei such as
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In this paper, we investigate the optical appearance of a charged black hole in the Kalb-Ramond background, incorporating a Lorentz-violating parameter\begin{document}$ l=0.01 $\end{document} ![]()
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. By analyzing the null geodesics, we derive the photon sphere, event horizon, effective potential, and critical impact parameters. We then employ a ray-tracing technique to study the trajectories of photons surrounding a thin accretion disk. Three different emission models are considered to explore the observed intensity profiles of direct rings, lensing rings, and photon sphere. By comparing these results with those of the standard Reissner-Nordström black hole (\begin{document}$ l=0 $\end{document} ![]()
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) and the Kalb-Ramond black hole with different values of Lorentz-violating parameter (specifically, \begin{document}$ l=0.05 $\end{document} ![]()
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and \begin{document}$ l=0.1 $\end{document} ![]()
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respectively), we find that the Lorentz symmetry breaking will lead to a decrease in the radii of the photon sphere, the event horizon, and the innermost stable circular orbit. Consequently, this makes the detection of these black holes more challenging.
In this paper, we investigate the optical appearance of a charged black hole in the Kalb-Ramond background, incorporating a Lorentz-violating parameter
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The orbital energy and momentum of the compact binary systems will loss due to gravitational radiation. Based on the mass and mass-current multipole moments of the binary system with the spin vector defined by Bohé et al. [Class. Quantum Grav. 30, 075017 (2013)], we calculate the loss rates of energy, angular momentum and linear momentum induced by the next-to-leading spin-orbit effects. For the case of circular orbit, the formulations for these losses are given in terms of the orbital frequency.
The orbital energy and momentum of the compact binary systems will loss due to gravitational radiation. Based on the mass and mass-current multipole moments of the binary system with the spin vector defined by Bohé et al. [Class. Quantum Grav. 30, 075017 (2013)], we calculate the loss rates of energy, angular momentum and linear momentum induced by the next-to-leading spin-orbit effects. For the case of circular orbit, the formulations for these losses are given in terms of the orbital frequency.
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Based on the Skyrme energy density functional, we systematically analyze the ratio\begin{document}$ T/U $\end{document} ![]()
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between the kinetic and potential energies for even-even nuclei at their ground states. We note that the nuclei with maximal value of \begin{document}$ T/U $\end{document} ![]()
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are generally stable nuclei for a certain isobaric chain with \begin{document}$ Z\le 82 $\end{document} ![]()
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. The known magic numbers can be more evidently observed from the ratio \begin{document}$ T/U $\end{document} ![]()
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comparing with nuclear binding energy, particularly for the isobaric chains with semi-magic nuclei. Combining the predicted binding energies and the ratios \begin{document}$ T/U $\end{document} ![]()
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from the Skyrme Hartree-Fock-Bogoliubov (HFB) code HFBTHO with parameters set UNEDF0, the possible magic numbers in super-heavy mass region are simultaneously studied. The neutron magic number \begin{document}$ N=184 $\end{document} ![]()
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can be clearly observed from the calculated values of \begin{document}$ T/U $\end{document} ![]()
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and the extracted microscopic energies of nuclei.
Based on the Skyrme energy density functional, we systematically analyze the ratio
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The evolution of nuclear shape and rotational behavior along the yrast line in even-even\begin{document}$ ^{126-136} {\rm{Ba}}$\end{document} ![]()
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has been systematically investigated using pairing self-consistent Woods-Saxon-Strutinsky calculation combined with the total Routhian surface (TRS) method in the (\begin{document}$ \beta_2, \gamma, \beta_4 $\end{document} ![]()
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) deformation space. Empirical laws are applied to evaluate nuclear ground-state properties, revealing a shape evolution from axially deformed to the non-axial vibrational configuration in even-even \begin{document}$ ^{126-136} {\rm{Ba}}$\end{document} ![]()
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isotopes. Particularly, an extreme γ-unstable shape is predicted in \begin{document}$ ^{130} {\rm{Ba}}$\end{document} ![]()
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. The shape transition of the ground state in these nuclei is confirmed by the TRS calculations. In addition, the evolution of the nuclear shape in high spin states with varying rotational axes associated with rotation around the medium, long, and short axes is illustrated by the TRS calculations. This variation is further characterized by the alignment of the \begin{document}$ \pi(h_{11/2})^2 $\end{document} ![]()
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and \begin{document}$ \nu(h_{11/2})^2 $\end{document} ![]()
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configurations, highlighting a preference for non-collective oblate/triaxial shapes with \begin{document}$ \gamma > 0^{\circ} $\end{document} ![]()
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and collective oblate/triaxial shapes with \begin{document}$ \gamma < 0^{\circ} $\end{document} ![]()
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, respectively.
The evolution of nuclear shape and rotational behavior along the yrast line in even-even
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This study explores black holes in General Relativity (GR) coupled with nonlinear electrodynamics (NED) in the presence of perfect fluid dark matter (PFDM). We derive a singular black hole solution and investigate its thermodynamic properties, including black hole temperature, entropy, and specific heat capacity of the black hole spacetime. The analysis of energy conditions reveals deviations from standard GR, with PFDM affecting the weak and strong energy conditions. The study further examines the impact of NED and PFDM on the innermost stable circular orbit (ISCO), demonstrating that PFDM shifts the ISCO radius and that combined effects of NED and PFDM field parameters sufficiently influence orbital stability. Our analysis of the black hole shadow reveals that PFDM increases the shadow radius while a higher charge reduces it, leading to modifications in potential astrophysical observables. The thermodynamic behavior of the black hole exhibits phase transitions marked by changes in heat capacity, indicating possible stability regimes. Moreover, we also derive equations for black hole shadow size and study the spacetime effects on the shadow. These results provide a framework for testing alternative gravity theories and understanding the role of exotic matter in strong gravitational fields. Finally, we compare the constraints on NED and PFDM field parameters derived from our black hole model with the Event Horizon Telescope (EHT) observations of M87* and Sgr A*, providing observational limits on deviations from General Relativity.
This study explores black holes in General Relativity (GR) coupled with nonlinear electrodynamics (NED) in the presence of perfect fluid dark matter (PFDM). We derive a singular black hole solution and investigate its thermodynamic properties, including black hole temperature, entropy, and specific heat capacity of the black hole spacetime. The analysis of energy conditions reveals deviations from standard GR, with PFDM affecting the weak and strong energy conditions. The study further examines the impact of NED and PFDM on the innermost stable circular orbit (ISCO), demonstrating that PFDM shifts the ISCO radius and that combined effects of NED and PFDM field parameters sufficiently influence orbital stability. Our analysis of the black hole shadow reveals that PFDM increases the shadow radius while a higher charge reduces it, leading to modifications in potential astrophysical observables. The thermodynamic behavior of the black hole exhibits phase transitions marked by changes in heat capacity, indicating possible stability regimes. Moreover, we also derive equations for black hole shadow size and study the spacetime effects on the shadow. These results provide a framework for testing alternative gravity theories and understanding the role of exotic matter in strong gravitational fields. Finally, we compare the constraints on NED and PFDM field parameters derived from our black hole model with the Event Horizon Telescope (EHT) observations of M87* and Sgr A*, providing observational limits on deviations from General Relativity.
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In the maximally-helicity-violating (MHV) configuration, tree-level single-trace Einstein-Yang-Mills (EYM) amplitude with one and two gravitons have been shown to satisfy a formula where each graviton splits into a pair of collinear gluons. In this paper, we extend this formula to more general cases. We provide a general formula which expresses tree-level single-trace MHV amplitudes in terms of pure gluon amplitudes, where each graviton turns into a pair of collinear gluons.
In the maximally-helicity-violating (MHV) configuration, tree-level single-trace Einstein-Yang-Mills (EYM) amplitude with one and two gravitons have been shown to satisfy a formula where each graviton splits into a pair of collinear gluons. In this paper, we extend this formula to more general cases. We provide a general formula which expresses tree-level single-trace MHV amplitudes in terms of pure gluon amplitudes, where each graviton turns into a pair of collinear gluons.
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Axially quadruple-octupole deformed relativistic Hartree-Fock (O-RHF) model with density-dependent meson-nucleon couplings is developed in this work, in which the reflection symmetry is not preserved anymore and the integro-differential Dirac equations are solved by expanding the Dirac spinor on the spherical Dirac Woods-Saxon basis. The reliability of the newly developed O-RHF model is illustrated by taking the octupole nucleus\begin{document}$ ^{144} {\rm{Ba}}$\end{document} ![]()
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as an example, and the octupole deformation effects in \begin{document}$ ^{144} {\rm{Ba}}$\end{document} ![]()
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is analyzed by using the RHF Lagrangians PKOi (\begin{document}$ i = 1,2,3 $\end{document} ![]()
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) and the RMF one DD-ME2. It is found that the O-RHF models reproduce the octupole deformation of \begin{document}$ ^{144} {\rm{Ba}}$\end{document} ![]()
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within the uncertainty of the experimental results. Moreover, the presence of the Fock terms can enhance the intrusion of the neutron \begin{document}$ 1i_{13/2} $\end{document} ![]()
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and proton \begin{document}$ 1h_{11/2} $\end{document} ![]()
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waves, which leads to an enhanced effects of octupole deformation for \begin{document}$ ^{144} {\rm{Ba}}$\end{document} ![]()
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. In particular, due to the repulsive tensor coupling between the intruding waves and the core of \begin{document}$ ^{144} {\rm{Ba}}$\end{document} ![]()
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, the tensor force component carried by the π-PV coupling, that contributes only via the Fock terms, is likely to play an unfavor role in the occurrence of the octupole deformation of \begin{document}$ ^{144} {\rm{Ba}}$\end{document} ![]()
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.
Axially quadruple-octupole deformed relativistic Hartree-Fock (O-RHF) model with density-dependent meson-nucleon couplings is developed in this work, in which the reflection symmetry is not preserved anymore and the integro-differential Dirac equations are solved by expanding the Dirac spinor on the spherical Dirac Woods-Saxon basis. The reliability of the newly developed O-RHF model is illustrated by taking the octupole nucleus
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We search for the leptonic decay\begin{document}$ D^+\to e^+\nu_{e} $\end{document} ![]()
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using an \begin{document}$ e^+e^- $\end{document} ![]()
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collision data sample with an integrated luminosity of 20.3 fb\begin{document}$ ^{-1} $\end{document} ![]()
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collected with the BESIII detector at the center-of-mass energy of 3.773 GeV, No significant signal is observed and an upper limit on the branching fraction of \begin{document}$ D^+\to e^+\nu_{e} $\end{document} ![]()
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is set as \begin{document}$ 9.7 \times 10^{-7} $\end{document} ![]()
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, at the 90% confidence level. Our upper limit is an order of magnitude smaller than the previous limit for this decay mode.
We search for the leptonic decay
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We propose the weak magnetic effect, which emerges in quark-gluon plasma close to local thermal equilibrium as the dissipative correction to the quark phase space distribution function, as a novel contribution to the observed Lambda hyperon local spin polarization. With a finite field strength, which is consistent with previous estimate of the magnetic field in heavy-ion collisions, one is able to explain the experimentally observed Lambda local spin polarization through all centrality classes. Moreover, the weak magnetic effect plays an unambiguous role in the ordering between the second-order and the third-order modulations of the Lambda local spin polarization in experiments.
We propose the weak magnetic effect, which emerges in quark-gluon plasma close to local thermal equilibrium as the dissipative correction to the quark phase space distribution function, as a novel contribution to the observed Lambda hyperon local spin polarization. With a finite field strength, which is consistent with previous estimate of the magnetic field in heavy-ion collisions, one is able to explain the experimentally observed Lambda local spin polarization through all centrality classes. Moreover, the weak magnetic effect plays an unambiguous role in the ordering between the second-order and the third-order modulations of the Lambda local spin polarization in experiments.
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Abstract:
In-ring nuclear reactions induced by light-ions, which are characterized by low-momentum sensitivity and low background, play an important role in nuclear structure and astrophysics investigations. Recently, the in-ring proton-nucleus elastic scattering measurements at low momentum transfer based on the internal hydrogen-gas-jet target have been successfully performed at the Cooler Storage Ring of the Heavy Ion Research Facility in Lanzhou (HIRFL-CSR). In this proceeding, we present the progress of matter radius measurements using the small-angle differential cross sections of proton-nucleus elastic scattering at the HIRFL-CSR.
In-ring nuclear reactions induced by light-ions, which are characterized by low-momentum sensitivity and low background, play an important role in nuclear structure and astrophysics investigations. Recently, the in-ring proton-nucleus elastic scattering measurements at low momentum transfer based on the internal hydrogen-gas-jet target have been successfully performed at the Cooler Storage Ring of the Heavy Ion Research Facility in Lanzhou (HIRFL-CSR). In this proceeding, we present the progress of matter radius measurements using the small-angle differential cross sections of proton-nucleus elastic scattering at the HIRFL-CSR.
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In this work, a comprehensive analysis of the mass spectra and decay properties of bottomonium states using a relativistic screened potential model is carried out. The mass spectrum, decay constants,\begin{document}$ E1 $\end{document} ![]()
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transitions, \begin{document}$ M1 $\end{document} ![]()
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transitions, and annihilation decay widths are evaluated. The interpretation of \begin{document}$ \Upsilon(10355) $\end{document} ![]()
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, \begin{document}$ \Upsilon(10580) $\end{document} ![]()
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,\begin{document}$ \Upsilon(10860) $\end{document} ![]()
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, and \begin{document}$ \Upsilon(11020) $\end{document} ![]()
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as \begin{document}$ S-D $\end{document} ![]()
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mixed bottomonium states are analysed. The \begin{document}$ \Upsilon(10355) $\end{document} ![]()
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state is considered to be \begin{document}$ 3S-2D $\end{document} ![]()
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, \begin{document}$ \Upsilon(10580) $\end{document} ![]()
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and \begin{document}$ \Upsilon(10753) $\end{document} ![]()
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are considered to be \begin{document}$ 4S-3D $\end{document} ![]()
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mixed states, and the \begin{document}$ \Upsilon(10860) $\end{document} ![]()
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and \begin{document}$ \Upsilon(11020) $\end{document} ![]()
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are deemed to be \begin{document}$ 5S-4D $\end{document} ![]()
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mixed states.
In this work, a comprehensive analysis of the mass spectra and decay properties of bottomonium states using a relativistic screened potential model is carried out. The mass spectrum, decay constants,
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We introduce a relative P-wave to construct the vector doubly-charm diquark\begin{document}$ (\widetilde{V}) $\end{document} ![]()
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, therefore, the scalar and tensor four-quark currents to investigate the decay widths of the fully-charm tetraquark states with the \begin{document}$ J^{PC}=0^{++} $\end{document} ![]()
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, \begin{document}$ 1^{+-} $\end{document} ![]()
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and \begin{document}$ 2^{++} $\end{document} ![]()
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via the QCD sum rules. We observe that the total width of the ground state \begin{document}$ \widetilde{V}\overline{\widetilde{V}} $\end{document} ![]()
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-type scalar tetraquark state is compatible with that of the \begin{document}$ X(6552) $\end{document} ![]()
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within the uncertainties, and the branching ratios are quite different from that of the first radial excitation of the \begin{document}$ A\bar{A} $\end{document} ![]()
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-type scalar tetraquark state. Other predictions can be verified in the future experiments to shed light on the nature of the fully-charm tetraquark states.
We introduce a relative P-wave to construct the vector doubly-charm diquark
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In order to study the coupling effect of positive Q-value two-neutron stripping channel in sub-barrier of\begin{document}$ ^{18} {\rm{O}}$\end{document} ![]()
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+ \begin{document}$ ^{50} {\rm{Cr}}$\end{document} ![]()
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, the fusion excitation functions have been measured for the \begin{document}$ ^{16,18} {\rm{O}}$\end{document} ![]()
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+ \begin{document}$ ^{50} {\rm{Cr}}$\end{document} ![]()
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systems at energies near and below the Coulomb barriers by using the electrostatic deflector setup. \begin{document}$ ^{16} {\rm{O}}$\end{document} ![]()
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+ \begin{document}$ ^{50} {\rm{Cr}}$\end{document} ![]()
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was selected as a reference system. The coupling effect of the low-lying collective excitation states in sub-barrier fusion was considered by the coupled-channels calculations. For \begin{document}$ ^{18} {\rm{O}}$\end{document} ![]()
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+ \begin{document}$ ^{50} {\rm{Cr}}$\end{document} ![]()
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, the coupled-channels calculated fusion cross sections, including the lowest 2\begin{document}$ ^+ $\end{document} ![]()
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vibrational states of the target nucleus and projectile, gives subtle under-estimation for the experimental ones at energies below the Coulomb barrier. This means limited room for transfer effect in \begin{document}$ ^{18} {\rm{O}}$\end{document} ![]()
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+ \begin{document}$ ^{50} {\rm{Cr}}$\end{document} ![]()
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, compared to the widely accepted argument of positive Q-value 2n-transfer remarkably enhancing the sub-barrier fusion cross sections. Analogous systems of neutron-rich \begin{document}$ ^{18} {\rm{O}}$\end{document} ![]()
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-induced fusion in existing literatures show the same peculiarity that positive Q-value two-neutron stripping channel has no remarkable influence on enhancing sub-barrier fusion cross sections.
In order to study the coupling effect of positive Q-value two-neutron stripping channel in sub-barrier of
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The configuration interaction relativistic Hartree-Fock (CI-RHF) model is developed in this work. Compared to the conventional configuration interaction shell model (CISM), the CI-RHF model can be applied to study the structural properties of a wide range of nuclei without readjusting any parameters, as the effective Hamiltonian for different model space can be deduced consistently from a universal density-dependent Lagrangian based on the Hartree-Fock single-particle basis. The convergence of intermediate-state excitations has been examined in evaluating the effective interactions, and the core-polarization effects are illustrated, by using\begin{document}$ ^{18} {\rm{O}}$\end{document} ![]()
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as an example. Employing the CI-RHF model, both the bulk properties and low-lying spectra of even-even nuclei \begin{document}$ ^{18\sim 28} {\rm{Ne}}$\end{document} ![]()
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have been well reproduced with the model space restricted to the \begin{document}$ sd $\end{document} ![]()
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shell. Studies of the isotopic evolution concerning charge radii and low-lying spectra highlight the shell closure at \begin{document}$ N=14 $\end{document} ![]()
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for neon isotopes. Furthermore, the cross-shell calculations extending from the \begin{document}$ sd $\end{document} ![]()
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to \begin{document}$ pf $\end{document} ![]()
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shell successfully reproduced the low-lying spectra of \begin{document}$ ^{30} {\rm{Ne}}$\end{document} ![]()
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and \begin{document}$ ^{32} {\rm{Ne}}$\end{document} ![]()
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. Notably, remarkably low excitation energies \begin{document}$ E(2^{+}_{1}) $\end{document} ![]()
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of \begin{document}$ ^{30} {\rm{Ne}}$\end{document} ![]()
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suggest the disappearance of the conventional magicity \begin{document}$ N=20 $\end{document} ![]()
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.
The configuration interaction relativistic Hartree-Fock (CI-RHF) model is developed in this work. Compared to the conventional configuration interaction shell model (CISM), the CI-RHF model can be applied to study the structural properties of a wide range of nuclei without readjusting any parameters, as the effective Hamiltonian for different model space can be deduced consistently from a universal density-dependent Lagrangian based on the Hartree-Fock single-particle basis. The convergence of intermediate-state excitations has been examined in evaluating the effective interactions, and the core-polarization effects are illustrated, by using
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The nuclear potential stands as a cornerstone in the study of nuclear structure and reaction. Research on the real part of nuclear potential has been well described by various models, while the imaginary part of nuclear potential remains insufficient. In this paper, a novel method is proposed to extract the imaginary nuclear potential from the high-precision excitation function of backward quasi-elastic scattering. The typical systems\begin{document}$ ^{16} $\end{document} ![]()
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O\begin{document}$ +^{152,154} $\end{document} ![]()
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Sm, \begin{document}$ ^{184,186} $\end{document} ![]()
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W with deformed target nuclei were analyzed. Nuclear imaginary potentials were obtained successfully by fitting the excitation functions within the single-channel and coupled-channels frameworks, respectively. A good reproduction at the energy range between sub- and above-barrier energy regions was achieved. Results show long-range imaginary part potential at a wide energy region covering the Coulomb barrier, consistent with the strong absorption for the well-deformed systems. This work is a preliminary attempt to bridge the gap between fusion and scattering and to extract the deformation parameters in the whole energy range. The subsequent systematic analysis needs to be further improved.
The nuclear potential stands as a cornerstone in the study of nuclear structure and reaction. Research on the real part of nuclear potential has been well described by various models, while the imaginary part of nuclear potential remains insufficient. In this paper, a novel method is proposed to extract the imaginary nuclear potential from the high-precision excitation function of backward quasi-elastic scattering. The typical systems
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The correlation\begin{document}$ \chi^{BQ}_{11} $\end{document} ![]()
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and quadratic fluctuations \begin{document}$ \chi^B_2,\ \chi^Q_2,\ \chi^T_2 $\end{document} ![]()
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of baryon number B, electric charge Q and temperature T are investigated in a two-flavor Polyakov loop extended Nambu-Jona-Lasinio (PNJL) model at finite temperature and magnetic field. The inverse magnetic catalysis (IMC) effect is introduced through the magnetic field dependent parameters \begin{document}$ G(eB) $\end{document} ![]()
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or \begin{document}$ T_0(eB) $\end{document} ![]()
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, and we make comparison of the results in the cases with and without IMC effect. With nonvanishing magnetic field, the correlation \begin{document}$ \chi^{BQ}_{11} $\end{document} ![]()
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and fluctuations \begin{document}$ \chi^B_2,\ \chi^Q_2,\ \chi^T_2 $\end{document} ![]()
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increase with temperature, and then show the peak around the pseudocritical temperatures of chiral restoration and deconfinement phase transitions in the cases with and without the IMC effect. The correlation and fluctuations along the phase transition line under external magnetic field are characterized by the scaled correlation \begin{document}$ {\hat {\chi}}_{11}^{BQ}=\frac{\chi_{11}^{BQ}(eB,T_{pc}^c(eB))}{\chi_{11}^{BQ}(eB=0,T_{pc}^c(eB=0))} $\end{document} ![]()
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and scaled fluctuations \begin{document}$ {\hat {\chi}}_2^{B(Q,T)}=\frac{\chi_2^{B(Q,T)}(eB,T_{pc}^c(eB))}{\chi_2^{B(Q,T)}(eB=0,T_{pc}^c(eB=0))} $\end{document} ![]()
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at the pseudocritical temperature \begin{document}$ T_{pc}^c $\end{document} ![]()
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of chiral restoration phase transition. \begin{document}$ {\hat {\chi}}_{11}^{BQ},\ {\hat {\chi}}_2^{B} $\end{document} ![]()
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, and \begin{document}$ {\hat {\chi}}_2^{Q} $\end{document} ![]()
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increase with magnetic fields, and the inclusion of IMC effect leads to some enhancement in their values. However, \begin{document}$ {\hat {\chi}}_2^{T} $\end{document} ![]()
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is altered by the IMC effect. Without IMC effect, \begin{document}$ {\hat \chi}^T_2 $\end{document} ![]()
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slightly increases and then decreases with magnetic fields. Taking into account of the IMC effect by \begin{document}$ G(eB) $\end{document} ![]()
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, \begin{document}$ {\hat \chi}^T_2 $\end{document} ![]()
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monotonically increases with magnetic fields, and by \begin{document}$ T_0(eB) $\end{document} ![]()
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, it is a nonmonotonic function of magnetic field.
The correlation
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This study investigates the consequences of Lorentz symmetry violation in the thermodynamics and gravitational lensing of charged black holes coupled to the Kalb-Ramond field. We first explore the impact of Lorentz-violating parameters on key thermodynamic properties, including the Hawking temperature, entropy, and specific heat, demonstrating significant deviations from their Lorentz-symmetric counterparts. Our analysis reveals that the Lorentz-violating parameter b induces modifications in phase transitions and stability conditions, offering novel insights into black hole thermodynamics. Additionally, the influence of Lorentz symmetry breaking on gravitational lensing is examined using modifications to the Rindler-Ishak method, showing that these effects enhance the bending of light near compact objects. Our findings, derived within the framework of the standard model extension and bumblebee gravity models, suggest that Lorentz-violating corrections could lead to observable astrophysical phenomena, providing potential tests for deviations from Einstein's theory of relativity.
This study investigates the consequences of Lorentz symmetry violation in the thermodynamics and gravitational lensing of charged black holes coupled to the Kalb-Ramond field. We first explore the impact of Lorentz-violating parameters on key thermodynamic properties, including the Hawking temperature, entropy, and specific heat, demonstrating significant deviations from their Lorentz-symmetric counterparts. Our analysis reveals that the Lorentz-violating parameter b induces modifications in phase transitions and stability conditions, offering novel insights into black hole thermodynamics. Additionally, the influence of Lorentz symmetry breaking on gravitational lensing is examined using modifications to the Rindler-Ishak method, showing that these effects enhance the bending of light near compact objects. Our findings, derived within the framework of the standard model extension and bumblebee gravity models, suggest that Lorentz-violating corrections could lead to observable astrophysical phenomena, providing potential tests for deviations from Einstein's theory of relativity.
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Several studies of fusion reaction dynamics have been focused on the impact of quadrupole\begin{document}$\beta_2^{\pm}$\end{document} ![]()
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deformation. However, existing literature highlights the importance of the octupole \begin{document}$\beta_3^{\pm}$\end{document} ![]()
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and hexadecapole \begin{document}$\beta_4^{\pm}$\end{document} ![]()
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deformations associated with both the projectile and target nuclei. However, the collective influence of these deformations \begin{document}$\beta_2$\end{document} ![]()
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,\begin{document}$\beta_3$\end{document} ![]()
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and \begin{document}$\beta_4$\end{document} ![]()
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on the fusion reaction dynamics has not been explored explicitly. The present study investigates the collective influence of higher order deformations, up to \begin{document}$\beta_4$\end{document} ![]()
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, on the barrier characteristics \begin{document}$V_B$\end{document} ![]()
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, \begin{document}$R_B$\end{document} ![]()
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, and \begin{document}$\hbar\omega$\end{document} ![]()
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, and their consequent impact on the fusion cross-sections of heavy-ion induced reactions in the mass range \begin{document}$163\leq{\rm{A}}\leq182$\end{document} ![]()
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. The reactions are examined at both compact and elongated configurations of the deformed nuclei. The investigation of heavy ion-induced reactions that consists of target nuclei with higher-order deformations, up to \begin{document}$\beta_4$\end{document} ![]()
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, reveals a notable alteration in the barrier characteristics \begin{document}$V_B$\end{document} ![]()
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and \begin{document}$R_B$\end{document} ![]()
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, along with a significant change in orientation \begin{document}$\theta_i$\end{document} ![]()
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for both compact and elongated configurations. In addition, the incorporation of deformations up to \begin{document}$\beta_4$\end{document} ![]()
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and their corresponding orientations \begin{document}$\theta_i$\end{document} ![]()
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contributes to enhanced capture cross-sections \begin{document}$\sigma_{cap}$\end{document} ![]()
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, as well integrated cross-sections \begin{document}$\sigma_{int.}$\end{document} ![]()
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, resulting in a better agreement with experimental data for \begin{document}$^{16}{\rm{O}}$\end{document} ![]()
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-induced reactions with \begin{document}$^{148}{\rm{Nd}}$\end{document} ![]()
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, \begin{document}$^{149-150}{\rm{Sm}}$\end{document} ![]()
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, and \begin{document}$^{32}{\rm{S}}$\end{document} ![]()
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-induced reactions with \begin{document}$^{150}{\rm{Sm}}$\end{document} ![]()
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. The study concludes that incorporation of deformations of all orders up to \begin{document}$\beta_4$\end{document} ![]()
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at their optimized compact and elongated configurations is essential as it provides better outcomes compared to the optimized configurations of \begin{document}$\beta_2$\end{document} ![]()
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and \begin{document}$\beta_3$\end{document} ![]()
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deformed nuclei.
Several studies of fusion reaction dynamics have been focused on the impact of quadrupole
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Abstract:
The study of black hole (BH) shadows provide crucial insights into the nature of strong gravitational effects and the intricate structure of the spacetime surrounding BHs. In this paper, we explore the shadow of Kerr MOG BH within a plasma environment, investigating how much the presence of plasma influences the characteristics of the observed shadow compared to those in vacuum conditions. Our analysis reveals that the shadow characteristics of M87* and Sgr A* are more compatible with event horizon telescope (EHT) observational data in nonhomogeneous plasma spacetime compared to homogeneous distributions. For small metric deformation parameter\begin{document}$ \alpha $\end{document} ![]()
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, the shadow aligns within \begin{document}$ 2\sigma $\end{document} ![]()
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uncertainty for homogeneous plasma and within \begin{document}$ 1\sigma $\end{document} ![]()
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for nonhomogeneous plasma. Next, we determine the energy emission rate for the Kerr MOG BH and analyze the influence of parameters α, \begin{document}$ k_o $\end{document} ![]()
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, \begin{document}$ k_\theta $\end{document} ![]()
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, and \begin{document}$ k_r $\end{document} ![]()
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on particle emissions in the BH vicinity. We further analyze the deflection angle in the presence of homogeneous and nonhomogeneous plasma profiles. The findings indicate notable differences from the vacuum scenario, underscoring the importance of accounting for plasma effects in studying light propagation around compact objects.
The study of black hole (BH) shadows provide crucial insights into the nature of strong gravitational effects and the intricate structure of the spacetime surrounding BHs. In this paper, we explore the shadow of Kerr MOG BH within a plasma environment, investigating how much the presence of plasma influences the characteristics of the observed shadow compared to those in vacuum conditions. Our analysis reveals that the shadow characteristics of M87* and Sgr A* are more compatible with event horizon telescope (EHT) observational data in nonhomogeneous plasma spacetime compared to homogeneous distributions. For small metric deformation parameter
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Abstract:
We investigate the soft behavior of the tree-level Rutherford scattering processes mediated via t-channel one-graviton exchange. We consider two types of Rutherford scattering processes, e.g., a low-energy massless structureless projectile (up to spin-1) hits a static massive composite particle carrying various spins (up to spin-2), and a slowly-moving light projectile hits a heavy static composite target. The unpolarized cross sections in the first type are found to exhibit universal forms at the first two orders in\begin{document}$ 1/M $\end{document} ![]()
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expansion, yet differ at the next-to-next-to-leading order, though some terms at this order still remain universal or depend on the target spin in a definite manner. The unpolarized cross sections in the second type are universal at the lowest order in projectile velocity expansion and through all orders in \begin{document}$ 1/M $\end{document} ![]()
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, independent of the spins of both projectile and target. The universality partially breaks down at relative order-\begin{document}$ v^2/M^2 $\end{document} ![]()
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, albeit some terms at this order still depend on the target spin in a specific manner.
We investigate the soft behavior of the tree-level Rutherford scattering processes mediated via t-channel one-graviton exchange. We consider two types of Rutherford scattering processes, e.g., a low-energy massless structureless projectile (up to spin-1) hits a static massive composite particle carrying various spins (up to spin-2), and a slowly-moving light projectile hits a heavy static composite target. The unpolarized cross sections in the first type are found to exhibit universal forms at the first two orders in
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We investigate the bound-state equations in two-dimensional QCD in the\begin{document}$ N_c\to \infty $\end{document} ![]()
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limit. We consider two types of hadrons, an exotic "meson" (which is composed of a bosonic quark and a bosonic anti-quark), and an exotic "baryon" (composed of a fermionic quark and a bosonic antiquark). Using the Hamiltonian operator approach, we derive the corresponding bound-state equations for both types of hadrons from the perspectives of the light-front quantization and equal-time quantization, and confirm the known results. We also present a novel diagrammatic derivation for the exotic "meson" bound-state equation in the equal-time quantization. The bound-state equation for the exotic baryons in the equal-time quantization in two-dimensional QCD is new. We also numerically solve various bound-state equations, obtain the hadron spectrum and the bound-state wave functions of the lowest-lying states. We explicitly demonstrate the pattern that as the hadron is boosted to the infinite-momentum frame, the forward-moving bound-state wave function approaches the corresponding light-front wave function.
We investigate the bound-state equations in two-dimensional QCD in the
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, doi: 10.1088/1674-1137/adc4ca
Abstract:
This article describes a series of studies on the effect of rotation of the fissile 236U nucleus in the 235U(n,f) process induced by monochromatic polarized neutrons with energies of 62 meV and 270 meV. The studied effect is expressed as a shift in the anisotropic angular distribution of γ-rays emitted by excited fission fragments by some small angle relative to the deformation axis of the fissile nucleus when the neutron beam polarization direction is reversed.All measurements were carried out at the Heinz Mayer-Leibniz research neutron source (FRM II reactor) of the Munich Technical University in Garching on the polarized neutron beam of the POLI instrument. To generalize all the results obtained on ROT effects for fission γ-rays, the results of earlier works by the ITEP group for cold neutrons are re-processed, and the result obtained for thermal neutrons by the PNPI group is also presented.
This article describes a series of studies on the effect of rotation of the fissile 236U nucleus in the 235U(n,f) process induced by monochromatic polarized neutrons with energies of 62 meV and 270 meV. The studied effect is expressed as a shift in the anisotropic angular distribution of γ-rays emitted by excited fission fragments by some small angle relative to the deformation axis of the fissile nucleus when the neutron beam polarization direction is reversed.All measurements were carried out at the Heinz Mayer-Leibniz research neutron source (FRM II reactor) of the Munich Technical University in Garching on the polarized neutron beam of the POLI instrument. To generalize all the results obtained on ROT effects for fission γ-rays, the results of earlier works by the ITEP group for cold neutrons are re-processed, and the result obtained for thermal neutrons by the PNPI group is also presented.
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In order to explore the possible existence of nuclear chirality in the\begin{document}$ A\approx 60 $\end{document} ![]()
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mass region, the doublet bands built on the configuration \begin{document}$ \pi f_{7/2}^{-1} \otimes \nu g_{9/2}^{1} $\end{document} ![]()
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are studied using the particle rotor model (PRM) with residual proton-neutron interactions \begin{document}$ V_{pn} $\end{document} ![]()
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for cobalt isotopes. The energy spectra \begin{document}$ E(I) $\end{document} ![]()
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, energy difference between the doublet bands \begin{document}$ \Delta E(I) $\end{document} ![]()
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, electromagnetic transition probabilities \begin{document}$ B(M1) $\end{document} ![]()
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and \begin{document}$ B(E2) $\end{document} ![]()
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, the energy staggering \begin{document}$ S(I) $\end{document} ![]()
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of the doublet bands are calculated by varying the deformation parameters β and γ, and moment of inertia \begin{document}$ \mathscr{J} $\end{document} ![]()
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. The PRM calculations show that the parameters for the ideal chirality of the configuration \begin{document}$ \pi f_{7/2}^{-1} \otimes \nu g_{9/2}^{1} $\end{document} ![]()
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are \begin{document}$ \beta=0.25 $\end{document} ![]()
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, \begin{document}$ \gamma=34^{\circ} $\end{document} ![]()
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, and \begin{document}$ \mathscr{J}=10\; \hbar^2/\rm MeV $\end{document} ![]()
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. Subsequently, PRM calculations adopting these parameters show that \begin{document}$ \Delta E(I) $\end{document} ![]()
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and \begin{document}$ S(I) $\end{document} ![]()
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are sensitive to the residual proton-neutron interactions \begin{document}$ V_{pn} $\end{document} ![]()
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. The weaker \begin{document}$ V_{pn} $\end{document} ![]()
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, the more conducive it is to the existence of nuclear chirality. Finally, the evolution of the chirality with spin I is illustrated by the probability of the total angular momentum along the principal axes (K distribution) and the orientation with respective to the intrinsic frame \begin{document}$ \mathscr{P}(\theta,\varphi) $\end{document} ![]()
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.
In order to explore the possible existence of nuclear chirality in the
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New liquid drop model with the iso-scalar volume and surface energy terms is applied to reproduce experimentally known masses of nuclei with number of protons and neutrons larger or equal to twenty. The ground-state microscopic energy corrections are taken into account. Even though the model contains only six adjustable parameters in the macroscopic part of the model, the quality of mass reproduction is good and comparable with other contemporary mass estimates. Also, the fission barrier heights of actinide nuclei evaluated using the topographical theorem of Myers and Świa̧tecki are close to the data.
New liquid drop model with the iso-scalar volume and surface energy terms is applied to reproduce experimentally known masses of nuclei with number of protons and neutrons larger or equal to twenty. The ground-state microscopic energy corrections are taken into account. Even though the model contains only six adjustable parameters in the macroscopic part of the model, the quality of mass reproduction is good and comparable with other contemporary mass estimates. Also, the fission barrier heights of actinide nuclei evaluated using the topographical theorem of Myers and Świa̧tecki are close to the data.
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Abstract:
We present the first lattice result of the near threshold\begin{document}$ \Lambda_c\Lambda_c $\end{document} ![]()
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scattering with \begin{document}$ I(J^P) = 0(0^+) $\end{document} ![]()
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. The calculation is performed on two \begin{document}$ N_f = 2+1 $\end{document} ![]()
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Wilson-Clover ensembles with pion mass \begin{document}$ m_\pi \sim 303 $\end{document} ![]()
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MeV and lattice spacing \begin{document}$ a = 0.07746 $\end{document} ![]()
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fm. The Lüscher's finite volume method is utilized to extract the scattering parameters from the finite-volume spectrum. The coupled channel \begin{document}$ \Xi_{cc}N $\end{document} ![]()
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is ignored in the scattering analysis based on the observation that the energy levels computed from the \begin{document}$ \Lambda_c\Lambda_c $\end{document} ![]()
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and \begin{document}$ \Xi_{cc}N $\end{document} ![]()
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operators do not mix. The \begin{document}$ \Sigma_c\Sigma_c $\end{document} ![]()
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channel is not included either since the energy range explored in this study is well below its threshold. Our results indicate that the interaction in the \begin{document}$ \Lambda_c\Lambda_c $\end{document} ![]()
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single channel is repulsive, and the scattering length is determined to be \begin{document}$ a_0 = -0.21(4)(8) $\end{document} ![]()
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fm, where the first error is the statistical error and the second is the systematic error.
We present the first lattice result of the near threshold
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Abstract:
The Nuclotron-based Ion Collider fAcility (NICA) is currently under construction at JINR, with the first beam tests of the Collider scheduled for the second half of 2025. The NICA project aims to provide colliding beams for studying heavy fully stripped ion collisions at energies of up to 4.5 GeV/u. The NICA accelerator complex comprises several components: the operational heavy ion linac HILAC with an energy of 3.2 MeV/u, the superconducting Booster synchrotron with a maximum energy of 600 MeV/u, the superconducting Nuclotron synchrotron capable of accelerating gold ions to 3.9 GeV/u, and two storage rings with two interaction points currently being installed. Two electron cooling systems are included—one in the Booster synchrotron with a maximum electron energy of 60 keV, and another in the Collider with two electron beams, each with a maximum energy of 2.5 MeV. Additionally, two stochastic cooling systems are implemented. The status of the NICA accelerator complex, including its cooling systems, is presented. Experimental results from electron cooling studies conducted during the commissioning of the injection complex are reported. Plans for further development and application of electron and stochastic cooling systems are also described.
The Nuclotron-based Ion Collider fAcility (NICA) is currently under construction at JINR, with the first beam tests of the Collider scheduled for the second half of 2025. The NICA project aims to provide colliding beams for studying heavy fully stripped ion collisions at energies of up to 4.5 GeV/u. The NICA accelerator complex comprises several components: the operational heavy ion linac HILAC with an energy of 3.2 MeV/u, the superconducting Booster synchrotron with a maximum energy of 600 MeV/u, the superconducting Nuclotron synchrotron capable of accelerating gold ions to 3.9 GeV/u, and two storage rings with two interaction points currently being installed. Two electron cooling systems are included—one in the Booster synchrotron with a maximum electron energy of 60 keV, and another in the Collider with two electron beams, each with a maximum energy of 2.5 MeV. Additionally, two stochastic cooling systems are implemented. The status of the NICA accelerator complex, including its cooling systems, is presented. Experimental results from electron cooling studies conducted during the commissioning of the injection complex are reported. Plans for further development and application of electron and stochastic cooling systems are also described.
ISSN 1674-1137 CN 11-5641/O4
Original research articles, Ietters and reviews Covering theory and experiments in the fieids of
- Particle physics
- Nuclear physics
- Particle and nuclear astrophysics
- Cosmology
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- Chinese Physics C Outstanding Reviewer Award 2023
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Cover Story
- Cover Story (Issue 1, 2025) Comments on Prediction of Energy Resolution inthe JUNO Experiment
- Cover Story (Issue 12, 2024) | Doubly heavy meson puzzle: precise prediction of the mass spectra and hadronic decay with coupled channel effects to hunt for beauty-charm family
- Cover Story (Issue 9, 2024) Measurement of solar pp neutrino flux using electron recoil data from PandaX-4T commissioning run
- Cover Story (Issue 11, 2024) ï½ Form factor for Dalitz decays from J/Ï to light pseudoscalars
- Cover Story (Issue 3, 2024) | First measurement of the ground-state mass of 22Al helps to evaluate the ab-initio theory